Washington to Chicago

What the Data Says About IAD to ORD

The Washington to Chicago corridor (IAD → ORD) covers roughly 588 miles and is served by 3 carriers, based on Bureau of Transportation Statistics reporting. Across 10,163 flights in the dataset, this route posts a 82.2% on-time rate with an average delay of 71.3 minutes when flights run late. Over the most recent 24 months of BTS data, 3,677 flights were recorded on this pairing — 24 cancelled (0.7%) and 6 diverted (0.2%). Those baseline metrics tell you what to expect before you book.

Having 3 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 10,163 total flights analyzed, the 82.2% on-time figure is statistically meaningful rather than a small-sample fluke. The 71.3-minute average delay applies only to flights that actually ran late, so it is not the average wait across all departures — the majority of flights on this route depart on time under the BTS definition of a delay (15+ minutes past schedule).

Looking at recent months, Mar 2024 posted the best performance on this corridor at 94% on-time, while Jul 2025 came in at 64% on-time — a 29-point gap between best and worst recent month. For travelers evaluating the IAD to ORD route, the combination of a 82.2% on-time rate, 71.3-minute average delay, 0.7% recent cancellation rate, and 3 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.